The present invention relates to a seat in general, and in particular to a seat in which the back element can be tilted or pivoted relative to the seat element. The invention is especially suitable for use in vehicle seats, such as the seats of automotive vehicles, but is generally applicable in other types of seats as well in which it is desired to be able to pivot the back element relative to the seat element.
Arrangements for permitting the back element to be pivoted relative to the seat element are already known in the prior art. They comprise two hinges located at opposite lateral sides of the seat and each connecting the back element to the seat element. They include a device which can be operated to permit the hinges--which are normally blocked against relative pivotal movement--to pivot so as to tilt the back element relative to the seat element.
The difficulty with the prior art is that the prior-art arrangements are not very safe in use. That is to say that they do not preclude the possibility of careless or even unintentional operation, for example during the movement of a motor vehicle provided with the seat, permitting the back element of the seat to tilt downwardly very quickly and surprisingly, and thereby startling the person on the seat and withdrawing back support for this person. If this occurs to the vehicle operator the result is likely to be an accident.
On the other hand, it is of course desired that the seat construction be such as to permit rapid tilting of the back element to a desired position, so that only fine adjustments need be made with the actual adjusting mechanism. Moreover, the back element must also be freely pivotable in forward direction upon operation of a release arrangement, at least if the seat is for example used in a two-door motor vehicle where ingress to and egress from the rear seat of the vehicle is possible only by tilting the back element of the front seat forwardly.